Which is better in a loop: post-increment (i++) or pre-increment (++i). | Sololearn: Learn to code for FREE!
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+ 26

Which is better in a loop: post-increment (i++) or pre-increment (++i).

Since the post-increment (i++) operator has to return the original value of i, and not the incremented value i + 1, it has to store the old version of i. This means that it typically needlessly uses additional memory to store that value, since, in most cases, we do not actually use the old version of i, and it is simply discarded. While pre-increment (++i), we do not have to save the old value of i — we can simply add to it and return. This aligns much better with the typical use-case in a for-loop, since we rarely need the old value of i in that context. My question is: when making a for-loop is it good practice to use a post-increment (i++) or pre-increment (++i)?

8th Nov 2019, 1:37 PM
Meny Evolving
Meny Evolving - avatar
35 Answers
+ 20
Surprisingly ++i is better than i++ since it's faster on the cpu. Here's the explanation: i++ does{ temp = i; i=i+1; return temp; } while ++i only does { i = i+1; return i; }
9th Nov 2019, 5:13 AM
Guillem Domènech
Guillem Domènech - avatar
+ 14
Aymane Boukrouh [Inactive] I often use the post-increment, which is also the most commonly use. I want opinion of other programmers as to which method is better so as to adopt.
8th Nov 2019, 2:16 PM
Meny Evolving
Meny Evolving - avatar
+ 12
I always write ++i, except when I specifically need the trait of i++ to change the value after the statement. From what I've heard, compiler optimizes i++ away anyway when possible, but I haven't really looked into compiled code.
8th Nov 2019, 2:41 PM
HonFu
HonFu - avatar
+ 8
~ swim ~ what is the difference in modern pc to execute i++ faster?
10th Nov 2019, 1:36 PM
ABADA S
ABADA S - avatar
+ 8
thanks ~ swim ~
10th Nov 2019, 1:53 PM
ABADA S
ABADA S - avatar
+ 7
The thing is that, you should be able to use them where they ought to be.... If you solely need to increment, you can use any of them. (i.e., pre/post)
9th Nov 2019, 2:10 AM
Abdul Samad
Abdul Samad - avatar
+ 7
Neither are best, you use the most appropriate one according to the needs of your code. ☺
10th Nov 2019, 7:04 AM
Haris
Haris - avatar
+ 7
Isn't it somewhat strange that the most overasked questions are also the most overanswered ones?
10th Nov 2019, 11:07 AM
HonFu
HonFu - avatar
+ 6
Guillem Domènech I think you did mean return temp
10th Nov 2019, 7:10 AM
ABADA S
ABADA S - avatar
+ 5
Post increment(i++) is better in case where we want i value increased in next step not in current step where as pre increment is good when we required instant increment in value of i that is in current step only. int i=2; Cout<<++i; //prints 3 Cout<<i++; //prints 2 Cout<<i;. //prints 3 This Is what is meant.
9th Nov 2019, 7:39 AM
Paras Waral
Paras Waral - avatar
+ 5
It is subjective - depending on the scenario.....
11th Nov 2019, 2:38 PM
Sanjay Kamath
Sanjay Kamath - avatar
+ 4
8th Nov 2019, 1:42 PM
Avinesh
Avinesh - avatar
+ 4
++i
9th Nov 2019, 8:28 AM
Sonic
Sonic - avatar
+ 4
Both are good, the choice is up to you.
10th Nov 2019, 2:42 AM
Meshach
Meshach - avatar
+ 4
HonFu Completely agree with you, it's after all just i++ and ++i.
10th Nov 2019, 11:10 AM
Avinesh
Avinesh - avatar
+ 3
++i
10th Nov 2019, 1:48 AM
Akil
+ 3
I personally like prefix
10th Nov 2019, 4:16 AM
OnesAndZeroes10
OnesAndZeroes10 - avatar
+ 3
With my little knowledge I was taught of i++ The other one I have come to learn here. Learning well here
10th Nov 2019, 4:42 AM
Phyllis Gikanga
Phyllis Gikanga - avatar
+ 3
Both are good at their place but pre-increment is good
10th Nov 2019, 6:06 AM
Rishu Dubey
Rishu Dubey - avatar